Small-molecule synergist of the Wnt/beta-catenin signaling pathway

Proc Natl Acad Sci U S A. 2007 May 1;104(18):7444-8. doi: 10.1073/pnas.0702136104. Epub 2007 Apr 25.


The Wnt/beta-catenin signaling pathway regulates cell fate and behavior during embryogenesis, adult tissue homeostasis, and regeneration. When inappropriately activated, the pathway has been linked to colorectal cancer and melanoma, and when attenuated it may contribute to Alzheimer's disease and osteoporosis. Small molecules that modulate Wnt signaling will likely provide new insights into the regulation of this key developmental pathway and ultimately provide pharmacological agents to control Wnt signaling in vivo. To this end, we screened a library of 100,000 small molecules for activity in a cell-based assay of Wnt/beta-catenin signaling and discovered a purine derivative, QS11, that synergizes with Wnt-3a ligand in the activation of Wnt/beta-catenin signal transduction. Through affinity chromatography and subsequent functional assays, we showed that QS11 binds and inhibits the GTPase activating protein of ADP-ribosylation factor 1 (ARFGAP1), suggesting that QS11 modulates Wnt/beta-catenin signaling through an effect on protein trafficking. Consistent with its function as an ARFGAP inhibitor, QS11 inhibits migration of ARFGAP overexpressing breast cancer cells.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line
  • Cell Movement / drug effects
  • Drug Evaluation, Preclinical
  • Humans
  • Molecular Structure
  • Purines / chemistry
  • Purines / pharmacology*
  • Signal Transduction / drug effects*
  • Wnt Proteins / metabolism*
  • Xenopus laevis
  • beta Catenin / metabolism*


  • Purines
  • QS11 compound
  • Wnt Proteins
  • beta Catenin